Integral $\int_0^\infty \exp(ia/x^2+ibx^2)dx$I have the book open in front of me too and there is an $i$, the integral Raymond says is not there. It's the appendix "Some useful definite integrals", integral A.3, emended edition, Dover edition (2010).

Integral $\int_0^\infty \exp(ia/x^2+ibx^2)dx$I found this integral in the context of a scattering problem in quantum mechanics. The result is in the appendix to "Quantum Mechanics and Path Integrals", by R.Feynman. I don't know in which sense it converges, hoped some mathematician may know